Elsevier

The American Journal of Medicine

Volume 125, Issue 11, November 2012, Pages 1125.e1-1125.e7
The American Journal of Medicine

AJM online
Clinical research study
Characteristics, Symptoms, and Outcome of Severe Dysnatremias Present on Hospital Admission

https://doi.org/10.1016/j.amjmed.2012.04.041Get rights and content

Abstract

Objective

Dysnatremias are common in critically ill patients and associated with adverse outcomes, but their incidence, nature, and treatment rarely have been studied systematically in the population presenting to the emergency department. We conducted a study in patients presenting to the emergency department of the University of Bern.

Methods

In this retrospective case series at a university hospital in Switzerland, 77,847 patients admitted to the emergency department between April 1, 2008, and March 31, 2011, were included. Serum sodium was measured in 43,911 of these patients. Severe hyponatremia was defined as less than 121 mmol/L, and severe hypernatremia was defined as less than 149 mmol/L.

Results

Hypernatremia (sodium > 145 mmol/L) was present in 2% of patients, and hyponatremia (sodium < 135 mmol/L) was present in 10% of patients. A total of 74 patients had severe hypernatremia, and 168 patients had severe hyponatremia. Some 38% of patients with severe hypernatremia and 64% of patients with hyponatremia had neurologic symptoms. The occurrence of symptoms was related to the absolute elevation of serum sodium. Somnolence and disorientation were the leading symptoms in hypernatremic patients, and nausea, falls, and weakness were the leading symptoms in hyponatremic patients. The rate of correction did not differ between symptomatic and asymptomatic patients. Patients with symptomatic hypernatremia showed a further increase in serum sodium concentration during the first 24 hours after admission. Corrective measures were not taken in 18% of hypernatremic patients and 4% of hyponatremic patients.

Conclusions

Dysnatremias are common in the emergency department. Hyponatremia and hypernatremia have different symptoms. Contrary to recommendations, serum sodium is not corrected more rapidly in symptomatic patients.

Section snippets

Materials and Methods

All patients in whom serum sodium was measured at the department of emergency medicine of a university hospital between April 1, 2008, and March 30, 2011, were included in this retrospective study. In patients who were admitted to the emergency department more than once, only the first admission was considered for the analysis.

Hyponatremia was defined as a serum sodium level less than 135 mmol/L, and hypernatremia was defined as a serum sodium level greater than 145 mmol/L. Severe hyponatremia

Results

Between April 1, 2008, and March 30, 2011, a total of 77,847 patients were admitted to the emergency department. Serum sodium was determined in 43,911 patients. The mean age of patients was 53 years (standard deviation, 20); 18,685 (43%) were women, and 25,226 (57%) were men. Hyponatremia (serum sodium < 135 mmol/L) was found in 4503 patients (10%), and hypernatremia (>145 mmol/L) was found in 678 patients (2%). The lowest serum sodium measured was 97 mmol/L, and the highest serum sodium

Discussion

Dysnatremias were present in 12% of all patients who were admitted to the emergency department. Symptoms were more common in hyponatremic patients than in hypernatremic patients. A significant proportion of patients did not receive corrective measures. Corrective measures were not more rapid in patients with symptomatic dysnatremias. A further increase in serum sodium was even observed in patients with symptomatic hypernatremia in the first 24 hours after admission.

Lee et al12 reported that 4%

Conclusions

Dysnatremias are common in patients presenting to the emergency department. Approximately one third of patients with severe hypernatremia and two thirds of patients with hyponatremia present with neurologic symptoms due to the electrolyte disorder. Symptomatic dysnatremias are not corrected faster than asymptomatic dysnatremias, although clear recommendations exist for this.

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    Funding: None.

    Conflict of Interest: None.

    Authorship: All authors had access to the data and played a role in writing this manuscript.

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